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481.
茶园土壤的有机质含量、腐殖质组成、有机碳的循环与平衡特点、酶活性及其在施肥条件下的变化情况与土壤肥力密切相关.试验结果表明:亚热带茶园土壤有机质含量水平较低,腐殖质组成中以富里酸为主,HA/FA比、酶活性均比起源土壤略低;高产茶园土壤有机碳库的循环水平较高,在不施有机肥的情况下仍能保持平衡;低产茶园土壤有机碳库的循环水平较低,输出大于输入,施用有机肥可以较快地提高茶园土壤有机质含量和酶活性水平.增施有机肥和实行茶林复合是培肥茶园土壤、提高茶园生产力的有效措施. 相似文献
482.
Chi-Wen Lin 《Environmental geochemistry and health》2002,24(1):23-33
For the past two decades, the Taiwan Environmental Protection Administration has made a systematic investigation of As, Cd, Cr, Cu, Pb, Hg, Ni and Zn in agricultural soils to identify soil pollution from industrial production. The EPA has cooperated with local governmental agencies to establish a soil quality monitoring system that would upgrade the land recovery ability and prohibit polluted lands from being cultivated or turned over to other uses. Based on an island-wide soil survey, more than 1,000 hectares of arable soils in Taiwan were found to be considerably contaminated by heavy metals. One of the heavy metal contaminated sites, located near a ceramic product manufacturing factory in Nantou County, was identified as lead contaminated. According to the Nantou Environmental Protection Bureau, the lead content in contaminated sites showed a great variation of several mg Pbkg–1 soil to several thousands mg Pbkg–1 soil. Therefore, it is appropriate to estimate the lead spatial distribution through geostatistics such as Kriging. The soil lead concentration contour maps obtained by Kriging can help us to identify the pollution patterns and delineate the range of contaminated sites. The purpose of this study is to determine the Pb concentrations at each location by performing detailed soil sampling on those Pb contaminated sites and estimating the lead spatial distributions by Kriging. A total of 70 soils were sampled from different locations at two experiment sites. Lead contents were determined with 0.1M HCl extractable lead content of the soils. The results obtained by investigating the lead contents in each 15cm segment down to a 60cm depth, revealed that lead contents were greater in arable land near the ceramic products manufacturing factory, and lead concentrations decreased with depth. In addition, Pb concentrations in heavily contaminated soils showed heavy concentrations of Pb in specific locations. Results from Pb content spatial distributions indicated that the Kriging model is a useful tool and can provide decision-makers with critical information for delineating hazardous areas in heavy metal contaminated sites. 相似文献
483.
484.
The inorganic ion concentrations of soils and streams in the three locations (Yorla, Zaakpon and Goi) in Ogoniland,Nigeria affected by crude oil spillage were investigated. In general, inorganic ion concentrations of polluted soilsand streams varied significantly (p = 0.05) from those of unpolluted soils and streams. Anions such as nitrate (NO
3
-
), sulphate (SO
4
2-
) and chloride(Cl-) showed significantly (p = 0.05) higher values inthe polluted soils and steams than in the unpolluted controls. The phosphate (PO
4
3-
) values were lowerin the polluted soils and streams than in the unpolluted controls.PO
4
3-
, NO
3
-
, SO
4
2-
and Cl- concentrations were generally significantly (p = 0.05) higher in soils and streams from Yorla, Zaakpon and their control than in Goi North, Goi South and Goi control.Exchangeable cations and trace metal concentrations weresignificantly (p = 0.05) higher in the polluted soils andstreams than in the unpolluted controls. Yorla and Zaakponpolluted soils and streams had higher concentrations of theexchangeable cations and trace metals compared to valuesfrom Goi, except for Na. Results also showed significantlyhigher values of heavy metals (Pb, Cd, Cr and Ni) in the polluted soils compared to their controls, and values werealso significantly (p = 0.05) higher in Yorla, Zaakpon andtheir control compared to Goi North, Goi South and Goicontrol. Values obtained in polluted streams were higherthan in the unpolluted though not significant at the 5%level (p = 0.05). The anionic and cationic concentrationsof Yorla and Zaakpon soils and streams were generally higherthan those of Goi, indicating that Yorla and Zaakpon areaswere more polluted than Goi.Although the concentrations of most of the anions andcations analysed in the polluted soils and streams werewithin the World Health Organisation's permissible valuesfor the protection of humans and environment, the streams ofYorla, Zaakpon and Goi are in general being polluted withinorganic ions. This may make these soils and streamsunacceptable for domestic and industrial uses if not treated,and soils (farmlands) may also become unsuitable for agricultural purposes. 相似文献
485.
486.
Böhme F Rinklebe J Stärk HJ Wennrich R Mothes S Neue HU 《Environmental science and pollution research international》2005,12(3):133-135
Background Estimations of gaseous mercury volatilization from soils are often complex, stationary and expensive. Our objective was to develop a mobile and more simple, easy to handle and more cost-effective field method allowing rapid estimates of potential Hg emissions from soils.
Methods. The study site is located in Germany, about 100 kilometers south-westerly of Berlin and influenced by the river Elbe and its tributary Saale river. The site is representative for a lot of other floodplain locations at the river Elbe and highly polluted with Hg and other heavy metals. For our study we developed a system consisting of a glass chamber gas, two gold traps, a battery operated pump and a gas meter. Adsorbed total gaseous mercury (TGM) in the gold traps was determined by use of atomic absorption spectrometry (AAS).
Results and Discussion. In contrast to the common used flux chambers we designed a chamber without inlet and named it gas suck up chamber (GSC). TGM fluxes determined with the GSC showed a very close linear correlation (r = 0.993) between the TGM content in the gold traps and the corresponding pumped gas volume. The TGM adsorbed, increased proportional with increasing gas volume indicating homogenous concentrations of gaseous mercury in the soil air sucked. In contrast to the commonly used dynamic flux chamber with the aim of precisely measuring actual fluxes of Hg from a defined soil area, we focused on developing of a measurement system which will allow rapid estimates of potential Hg emissions of a site. Earlier research at the study site indicated a high potential for releasing volatile Hg from the soil to the atmosphere. Indeed, due to the high Hg content of the soil significant amounts of TGM could be detected and no shortage was reached.
Conclusion. Our initial measurements are still too few in number neither to generalize the achieved results nor discuss controlling factors and processes. However, we are pleased to communicate that the developed GSC is well suited to become an effective sampling set up to rapidly estimate the magnitude of Hg volatilization from soils.
Outlook. Further measurements at other polluted locations are necessary to verify the GSC method. In addition the use of a mercury analyzer instead of gold traps is planned for faster risk assessments. 相似文献
487.
Jones PD Newsted JL Henningsen G Slocomb J Giesy JP 《Environmental science and pollution research international》2005,12(4):189-198
Background, Aims and Scope The Rocky Mountain Arsenal (RMA) is a US Army facility located northeast of Denver, Colorado that has been listed on the
National Priorities List (NPL). It is currently being re-mediated under the authority of the Comprehensive Environmental Response,
Compensation, and Liability Act of 1980 (CERCLA) and the Superfund Amendments and Reauthorization Act of 1986 (SARA). As part
of the remediation activities at RMA, indications were found that a source of polychlorinated dibenzo-p-dioxins (PCDDs) and
polychlorinated dibenzofurans (PCDFs) had existed on the RMA. As a result, investigations were undertaken to assess the possible
nature and extent of any potential sources of PCDDs and PCDFs on the RMA site. In addition, other studies were conducted that
examined PCDD/PCDF contamination in the Denver area. The goal of these studies was to examine nature and extent of PCDD/PCDF
contamination both on the RMA as well as in the surrounding Denver area. The intent of this study was to characterize sources
of dioxins (PCDDs) and dibenzofurans (PCDFs) at low environmental concentrations which might have originated from diffuse
sources in the Denver Colorado area and in particular, the Rocky Mountain Arsenal (RMA) using Principal Component Analysis
(PCA).
Methods Over 200 soil samples were collected from the RMA and the Denver area. From the RMA, soil was collected as part of three
studies that included a (1) random site-wide sampling of the RMA, (2) soils from the Western Tier Parcel (WTP), and (3) soils
from Historic Use areas. Denver area soil samples were collected from five different land use categories: Residential, Agricultural,
Open Space, Commercial, and Industrial. PCA was conducted on concentrations of 17 2,3,7,8-substuituted PCDD and PCDF congeners
in 220 soil samples collected from the RMA and the Denver Front Range region.
Results and Discussion PCA demonstrated the presence of possible minor sources of dioxins on the RMA. Current remediation efforts on RMA will result
in the removal of these sources. Samples from the RMA were identified by the presence of a congener profile containing higher
chlorinated PCDFs while the Denver Front Range areas were characterized by the presence of higher chlorinated PCDD congeners.
The presence of a PCDF signature for the RMA samples does not necessarily indicate a major source of these contaminants on-site.
Indeed, the relatively diffuse nature of the sample clusters would argue strongly against the presence of a single large source.
Instead, the predominance of the PCDF congeners probably indicates the mixed industrial activities that took place on and
near the site.
Conclusion PCA results indicate that PCDD/PCDF profiles in soils collected from the RMA differed from those collected from the outlying
Denver areas but that a major source of these contaminants was not present. Rather, the diffuse nature of sample clusters
from the PCA indicated that the congener profile of RMA samples was most likely a result of the mixed industrial activities
that historically have taken place on and near the site. PCA also indicated that many of the 'open area' (peripheral site-wide)
RMA soils samples did not differ from Denver are reference congener profiles. This finding was also true for samples collected
from the WTP that were essentially indistinguishable from Off-RMA reference samples. In addition, total TEQ concentrations
in soils collected from WTP were similar to those measured in soils collected from the Denver Front Range areas indicating
that lack of a major source of PCDD/PCDF within the WTP zones of the RMA.
Recommendation and Outlook Analytical as well as statistical results of the soil congener data indicate that the WTP soils are indistinguishable from
soils collected from non-industrial areas in the Denver area. This finding would support the recent 'de-listing' of the WTP
from the other RMA areas and its' transfer to other authorities in the Denver area. 相似文献
488.
不同相伴阴离子对镉污染红壤微生物区系及群落功能多样性的影响 总被引:8,自引:1,他引:8
通过外加醋酸镉和氯化镉的室内培养试验研究了不同相伴阴离子对镉污染红壤中微生物区系及群落功能多样性的影响 .结果表明 :在相同镉浓度下相伴OAc-对镉污染红壤的细菌、放线菌和真菌数量及微生物群落功能多样性的抑制作用大于相伴Cl-.统计分析显示 ,在供试红壤中OAc-与Cl-对其微生物区系及微生物群落代谢剖面 (AWCD值 )、Shannon指数的影响均达到显著差异 (P <0 0 5 ) ,且在红砂土上表现更为明显 .外加醋酸钾和氯化钾的培养试验结果表明 ,阳离子为钾时 ,相伴OAc-与Cl-对红壤微生物区系结构及群落功能多样性没有产生明显抑制作用 ,相伴OAc-甚至存在一定的刺激作用 .可见 ,相伴OAc-对镉污染红壤微生物的毒害作用大于相伴Cl-,其原因并非是阴离子本身的毒性效应 ,而镉的生物有效性变化可能是不同相伴阴离子镉盐导致毒性差异的原因之一 . 相似文献
489.
490.